In-line gun type color television picture tube apparatus

ABSTRACT

An in-line gun type color television picture tube apparatus in which electron beam spots are converged at any point on the screen by a convergence magnetic field in order to symmetrically shift the electron beams from the electron guns at both sides out of three electron guns, which are provided in one line of the inline electron gun type color cathode-ray tube, in reference to the electron beam from the center electron gun.

United States Patent 1191 Saruta IN-LINE GUN TYPE COLOR TELEVISION PICTURE TUBE APPARATUS [75] Inventor: Sadayoshi Saruta, Yokohama, Japan [73] Assignee: Denki Onkyo Co., Ltd., Tokyo,

Japan 22 Filed: June 22,1972

21 Appl. 190.; 265,254

[30] Foreign Application Priority Data June 23, 1971 Japan 46-45429 [52] US. Cl. 315/13 CG, 315/13 C, 315/27 XY, 315/27 GD [51] Int. Cl. HOlj 29/50 [58] Field of'Search 315/13 C, 13 CG, 27 XY, 315/27 TD, 27 GD; 335/213; 313/68 A [5 6] References Cited UNITED STATES PATENTS 3,325,675 Sanford 315/13 C Apr. 23, 1974 3,553,523 1/1971 Budd 315/13 c 3,028,521 4/1962 Szegho 315 31 TY 3,117,253 1/1964 Allen 335/213 3,500,114 3/1970 Sawai 315/13 c 3,613,109 10/1971 Jarosz 315/13 c 3,622,927 11/1971 Washburn 335/213 x Primary ExaminerLeland A. Sebastian AssistanLE tgminer P. A. Nelson Attorney, Agent, or Firm Armstrong & Wegner [5 7] ABSTRACT An in-line gun type color television picture tube apparatus in which electron beam spots are converged at any point on the screen by a convergence magnetic field in order to symmetrically shift the electron beams from the electron guns at both sides out of three electron guns, which are provided in one line of the in-line electron gun type color cathode-ray tube, in reference to the electron beam from the center electron gun.

17 Claims, 13 Drawing Figures MTEMTEBAPR 23 1974 SHEET 1 BF 7 FIGZ 17M TEDAPR 23 I974 SHEET 2 OF 7 FIG4 PATENTED APR 2 3 m4 SHEET 3 OF 7 FIGSD IN-LINE GUN TYPE COLOR TELEVISION PICTURE TUBE APPARATUS BACKGROUND OF THE INVENTION The present invention relates to an in-line gun type color television picture tube apparatus in which three electron guns are arranged in one line.

For obtaining high quality image on the screen of this type of the cathode-ray tube, three electron beams are preferred to reach a group of fluorescent materials at any position where electron beams are extemely close each other on the screen when the electron beams hit on three colors of fluorescent materials which are painted in dots or lines. Therefore, an aperture frame having dot-type or slit-type openings such as, for example, a shadow mask or aperture grill is provided between the screen and electron guns and electron beams are preferred to be converged at each opening with specified angles.

In case of a wide angle deflection cathode-ray tube of which the screen is almost flat, the distance between the screen and the electron guns differs with the deflection angle, that is, the greater the deflection angle is, the longer the distance.

Accordingly, even though the electron guns are arranged so that the electron beams are converged at the center of the screen (the electron beams are actually converged at the openings of the aperture frame; however, the aperture frame is positioned close and parallel to the screen and therefore the electron beams are described as being converged at the screen for convenience), the electron beams are diverged at a portion where the deflection angle is large, that is, a peripheral portion of the screen. For this reason, the convergence operation to converge electron beams in accordance with the deflection angle, that is, the so-called dynamic convergence operation is performed.

Conventionally, convergence has been performed in such the manner that electrodes are provided in the cathode-ray tube, a converging device is provided outside the cathode-ray tube corresponding to the electrodes and relative angles of the electron beams are controlled at the position before the electron beams are deflected. Accordingly, the conventional type cathoderay tube is disadvantageous because it has been complicated in its construction and the convergence device has employed a complex-shaped yoke corresponding to the electrodes in the cathode-ray tube.

The present invention provides a cathode-ray tube which requires no electrode for convergence in the cathode-ray tube and is capable of specifically converging the electron beams through an extremely simple construction.

SUMMARY An in-line gun type color television picture tube apparatus comprising an in-line gun type color cathoderay tube in which the spots on the screen of electron beams from free electron guns provided in one line are aligned on the same line and are converged at the center of the screen, a deflection yoke which deflects and scans the electron beams so that both side spots appear on the screen with equal distance symmetrically at both sides of the center spot when three electron beams are not converged, and a convergence magnetic field generating means which forms a convergence magnetic field having a field distribution linear-symmetrical in reference to two axes, as the reference line, which are biased respectively by 45 from the direction of three electron guns aligned in one line and the direction intersecting at a right angle to said direction of the electron guns in reference to the axis of the cathode-ray tube by, for example, providing the windings at specified positions on the core of said deflection yoke and supplying the convergence current to said windings, wherein both side electron beams are symmetrically shifted in reference to the center electron beam in accordance with the deflection angle, in order to complete convergence of the beam spot trio through said convergence magnetic field.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated in detail at the accompanying drawings whereon:

FIG. 1 is a cross sectional plan view illustrating an embodiment of a convergence magnetic field generating means of the apparatus according to the present invention,

FIG. 2 is a front view of a screen illustrating the position of the beam spot trio,

FIG. 3 is a longitudinal sectional view of a cathoderay tube illustrating an embodiment of a convergence magnetic field generating means of the apparatus according to the present invention,

FIG. 4 is an example of the convergence current supplied to said convergence magnetic field generating means,

FIGS. 5a, 5b and 5c are respectively an embodiment of the convergence magnetic field generating means; FIGS. 5a and 5b are an isometric view of a partially magnified convergence winding, and FIG. 5c is a cross sectional plan view of the cathode-ray tube, and

FIGS. 6a to 6f are respectively a circuit diagram illustrating an embodiment of the convergence magnetic field generating means.

DETAILED DESCRIPTION Referring to FIG. 1, there is shown a rough construction of the apparatus according to the present invention.

Three electron guns 2, 2 and 2" are arranged on one line in the rear end plane of neck 12 of cathode-ray tube 1 and aperture frame 3 such as, for example, a shadow mask or an aperture grill, having a plurality of openings 31 such as through holes or slits is provided near the screen between screen 11 and the electron beams.

Electron guns 2, 2' and 2" are slanted so that electron beams 21, 22 and 23 radiated from the electron guns intersect at one point in the opening through which center axis 0 of selection frame 3 passes.

Deflection yoke 4 is mounted at neck 12 of cathoderay tube 1 and convergence coil 5 is provided at the rear end of the deflection coil which induces the convergence magnetic field.

In the above arrangement, cathode-ray tube 1 and electron guns 2, 2 and 2" are known as the in-line type cathode-ray tube and therefore can be designed as desired as in case of conventionally known in-line type color television picture tubes.

In deflection yoke 4, the electron beams are deflected in the electron gun aligning direction such as, for example, a horizontal direction and a direction at a right angle to said direction such as, for example, a

vertical direction. In this case, deflection in the horizontal direction is performed in a far shorter cycle than that in the vertical direction to form a raster on the screen of the picture tube.

As described in Background of the Invention, the electron beams diverge depending on the deflection angle even though the electron beams are forced to concentrate at center on screen 11. In the embodiment of the present invention, it can be understood that the electron beams are diverged on the screen in a relatively simple pattern depending on the deflection field of the deflection yoke and the curvature of the screen.

Referring to FIG. 2, there is shown the characteristic of the electron beam spot trio appearing on screen 11 through the deflection yoke of the apparatus according to the present invention.

The beam spot trio is an assembly of spot 211 formed by electron beam 21 radiated onto, for example, a red fluorescent material, spot 221 formed by electron beam 22 radiated onto, for example, a blue fluorescent material and spot 231 formed by electron beam 23 radiated onto, for example, a green fluorescent material. In a special line containing center 0 of the screen, that is, the special line such as, for example, horizontal line 1 which coincides with the direction in which electron beams 21, 22 and 23 are arranged, the electron beams are deflected so that the distance between the spots increases as the spots depart from a line intersecting at a right angle to said special line at center 0 such as, for example, vertical line 1'. In a direction parallel with vertical line I, the electron beams are deflected so that the distance between the spots increases as the spots depart from vertical line 1'.

In other words, the electron beams are deflected in the deflection field so that the electron beams are symmetrically diverged in reference to horizontal line 1 and vertical line 1. Such the deflection field characteristic can be easily realized.

The convergence magnetic field which is the most important feature of the apparatus according to the present invention converges the electron beams which are diverged as described above.

Referring to FIG. 3, there is shown an embodiment of convergence coil of the apparatus according to the present invention.

Three electron beams 21, 22 and 23 are aligned on one line in neck 12 of cathode-ray tube 1 and core 51 consisting of a circular highly magnetic material is mounted on the periphery of neck 12.

A pair of windings 521 and 522 are toroidally wound on core 51 at symmetrical positions in the same direction as said electron guns are aligned, and a pair of windings 523 and 524 are toroidally wound at symmetrical positions in the direction intersecting at a right angle to the same direction as the electron guns are aligned.

The windings are series-connected to power supply 53 which supplies convergence current 1 to said windings so that the magnetic fluxes from adjacent windings flow in opposite directions in the core. If the windings are wound on core 51 in the same direction, the windings are connected so that directions d of the currents in adjacent windings are opposite each other, and magnetic field M, from winding 521 shown in the figure, magnetic field M from winding 522, magnetic field M from winding 523 and magnetic field M, from winding 524 are induced respectively.

Since the magnetic fields show a linear symmetrical distribution of the magnetic field in reference to two axes x and y shifted by 45 degrees from the electron gun aligning direction and the direction intersecting, at center axis 0 of cathode-ray tube 1, at a right angle to the same direction as the electron guns are aligned, magnetic fields M and M do not affect the electron beams and magnetic fields M and M do not affect electron beam 23 at center axis 0 of cathode-ray tube 1. Accordingly, the magnetic force affecting electron beams comes from only magnetic field M, affecting electron beam 21 and magnetic field M affecting electron beam 23. This magnetic force causes said electron beams to be symmetrically shifted in reference to center electron beam 22.

As described in the foregoing, divergence of the electron beams appears markedly in the vertical direction and is symmetrical in reference to horizontal line containing center 0 of the screen. Electron beams 21 and 23 at both sides of center electron beam 22 diverge in the horizontal direction and are symmetrical in vertical line 1'. Accordingly, three beam spots 21 1, 221 and 231 can be converged at all positions on the screen by varying the magnetic fields in accordance with the deflection angles.

As shown in FIG. 4, convergence current 1 superposed on a parabola type current of horizontal deflection cycle D and a parabola type current of vertical deflection cycle Dy can be supplied from power supply 53. In FIG. 4, a white round mark indicates the current value in the beginning of the horizontal deflection cycle and a black round mark indicates the current value at the end of the horizontal deflection cycle. The time between these timings is the flyback time. Convergence current 1 as shown in FIG. 4 has been applied to conventional televison picture tubes and therefore it can be employed as is.

It is known generally that the deviation of relative angles is minimum at the points which the electron beams reach when convergence is performed at the deflecting point for scanning electron beams.

Accordingly, the so-called mislanding" that electron beams do not arrive properly at the centers of corresponding fluorescent materials even though convergence of the electron beams is satisfactorily performed is prone to occur when the deflection scanning positions of electron beams are different from the convergence positions.

If the coils of the deflection yoke are toroidally wound, a highly magnetic core is employed and therefore core 51 of the convergence coil and the core of the deflection yoke can be employed commonly. In other words, the windings of the convergence coil can be mounted on the core of the deflection yoke. Accordingly, the deflection center of the deflection yoke can be matched with the convergence position and thus mislanding can be minimized.

If one set of deflection coils, for example, the horizontal deflection coils are wound toroidally and the other set of deflection coils, for example, the vertical deflection coils are wound in the frame shape, a convergence coil is wound, around the core of the vertical deflection coil.

The windings of said convergence coil need not be toroidally wound and if they are wound in the frame shape, the magnetic field as described above can be generated.

Referring to FIG. 5, there is shown an embodiment of the apparatus according to the present invention where the windings of the convergence coil are wound in the frame shape.

Four sets of frame-shaped windings 521', 522', 523 and 524' are provided at symmetrical positions in the direction at 45 to the direction in which electron guns 2, 2' and 2" are aligned on the periphery of neck 12 of cathode-ray tube 1. And the cathode-ray tube is constructed so that magnetic field M is induced between windings 521' and 522, magnetic field M between windings 522' and 523, magnetic field M between windings 523' and 524' and magnetic field M between windings 524' and 521 Magnetic fields in the cathoderay tube is distributed so that the magnetic fields at mutually opposing positions has symmetricity as in the case of the embodiment shown in FIG. 3.

When the frame-shaped winding is employed, two pairs of windings need not be provided. For example, as shown in FIG. 5b, a pair of frame-shaped windings 522' and 524 can be arranged only at the position of axis y which deflects 45 in one direction from the direction from which electron beams 21, 22 and 23 are originated. The magnetic fields having a similar distribution to that in case that two pairs of windings are arranged because magnetic fluxes induced by both windings 522' and 524 repulse each other.

When convergence coil 5 is thus comprised of the frame-shaped winding, it can be provided inside deflection yoke 4, that is, between deflection yoke 4 and neck 12 of cathode-ray tube 1 as shown in FIG. 5c. In this arrangement, convergence can be performed at the deflection center of the deflection yoke.

At the position where the magnitude of deflection is large, electron beams 21, 22 and 23 may be affected by other convergence magnetic fields, not by the intrinsically corresponding magnetic field; for example, center electron beam 22 may deviate from center axis and may be affected by either magnetic field M or M For this reason, it is desirable to provide convergence coil at a position near the electron guns in deflection yoke 74 as shown so that the magnetic field does not exist at a position near screen 11 in deflection yoke 4.

If at least one of the horizontal deflection coil and vertical deflection coil is toroidally wound, the position of the toroidally wound deflection coil corresponds to the toroidal winding of the convergence coil. Accordingly, the convergence coil need not be provided additionally and convergence current I superposed on the deflection current can be supplied.

For example, as shown in FIG. 6a, if a pair of windings 41 and 41' of the horizontal deflection coil are wound in the frame shape at opposing positions and a pair of windings 42 and 42' of the vertical deflection coil are toroidally wound at opposing positions, a pair of windings 521 and 522 are toroidally wound on core 43 of the windings of the vertical deflection coil at the position at 90 to vertical deflectfin vvfnmngs a and 42', that is, at symmetrical positions in the direction from which electron beams 21, 22 and 23 are originated, in reference to axis 0 of cathode-ray tube 1. Vertical deflection current I and convergence current I are supplied to vertical deflection windings 42 and 42 through distribution transformer T so that both currents do not interfere each other and, at the same time,

convergence current I is supplied to windings 521 and 522 exclusively used for convergence.

Vertical deflection power supply S is connected to the primary winding of distribution transformer T, both windings 42 and 42' of the vertical deflection coil are series-connected across terminals T and T at both ends of the secondary winding, and convergence windings 521 and 522 and convergence power supply 53 are series-connected between the intermediate connecting point 42a of both windings and center terminal T of the secondary winding.

If convergence current I is supplied as shown with a broken line and arrow in the figure so that the current flows in opposite directions along the circumferential direction in adjacent windings which are all wound in the same direction, for example, in the counterclockwise direction, magnetic fields M M M and M, which are symmetrical in reference to tube axis 0 are induced. Under this condition, vertical deflection current I flows in vertical deflection coils 42 and 42' but does not flow in convergence windings 521 and 522 because the potential at intermediate connecting point 42a between both vertical deflection coils 42 and 42' is equal to that at center terminal T of the secondary winding of the distribution transformer.

Both convergence windings 521 and 522 can be parallel-connected as shown in FIG. 6b.

Distribution transformer T can be employed for convergence power supply 53. For example, as shown in FIG. 6c, the primary winding of distribution transformer T can be connected to convergence power supply 53, convergence windings 521 and 522 and both vertical deflection windings 42 and 42 can be respectively series-connected between terminals T, and T of the secondary winding, and vertical deflection power supply S can be connected between intermediate connecting point 42b of vertical deflection windings 42 and 42 and center terminal T of the secondary winding of distribution transformer T.

If both the vertical deflection coil and the horizontal deflection coil are toroidally wound, convergence current I superposed on horizontal deflection current I or vertical deflection current I can be supplied to said both deflection coils. For example, as shown in FIG. 6d, vertical deflection power supply Sy is connected to the primary winding of one distribution transformer T of two distribution transformers T and T", windings 42 and 42' of the vertical deflection coil are seriesconnected between terminals T and T of the secondary winding, horizontal deflection power supply 5,, is connected to the primary winding of other distribution transformer T", and windings 41 and 41' of the horizontal deflection coil are series-connected between terminals T and T of the secondary winding.

Convergence power supply 53 is connected to the primary winding of dividing transformer T having a pair of independent secondary windings C and C one secondary winding C of dividing transformer T is connected between center terminal T of the secondary winding of distribution transformer T' for vertical deflection and intermediate connecting point 42c of vertical deflection windings 42 and 42, and the other secondary winding C is connected between center terminal T of the secondary winding of distribution transformer T" for horizontal deflection and intermediate connecting point 42d of horizontal deflection windings 41 and 41'.

When convergence current I,- is supplied to both the vertical deflection coil and horizontal deflection coil as described above, the distribution transformer can be employed for the convergence power supply as shown in FIG. 46.

The distribution transformer is comprised of a pair of independent secondary windings C and C respectively provided with three terminals. Transformer T is formed so that center terminal T of one secondary winding C is positioned at the electrical center between terminals T and T at both ends and center terminal T of other secondary winding C is positioned at the electrical center between terminals T and T at both ends. Primary winding C" is connected to convergence power supply 53 and vertical deflection windings 42 and 42 are series-connected between terminals T and T of one secondary winding C, vertical deflection power supply S is connected between intermediate connecting point 420 of vertical deflection windings 42 and 42' and center terminal T horizontal deflection windings 41 and 41 are series-connected between terminals T and T of other secondary winding C, and horizontal deflection power supply S is connected between intermediate connecting point 42d of horizontal deflection windings 41 and 41.

As shown in FIG. 4a, if the convergence current superposed, on the deflection current is supplied to one pair of deflection windings 42 and 42 and the convergence current alone is supplied to windings 521 and 522, the convergence current can be supplied from separate convergence power supply 53' to windings 521 and 522 exclusively employed as shown in FIG. 4f.

Thus, if the toroidally wound deflection coils are employed, convergence can be easily performed without providing a separate convergence coil and is performed at the deflection and scanning position.

As described above, when both side electron beams are diverged symmetrically in reference to the center electron beam, the convergence of electron beams can be easily performed at any position on the screen by supplying the convergence current, of which the amplitude varies in accordance with divergence, to the convergence coil. Accordingly, the apparatus of the present invention is advantageous because the convergence electrodes need not be provided in the cathode-ray tube and a deflection yoke in a complicated shape corresponding to said electrodes need not be provided. In particular, the apparatus is advantageous because the electron beams can be shifted for convergence at the center of deflection to effectively prevent mislanding and the convergence current superposed on the deflection current can be supplied to the toroidally wound deflection coil, thus simplifying the construction of the apparatus.

What is claimed is:

1. An in-line gun type color television picture tube apparatus comprising:

a. an in-line gun type color cathode-ray tube in which three electron guns are arranged in a line along a first axis and the spots of electron beams from these electron guns appear along the first axis on the screen of the cathode-ray tube and are converged at the center of the screen,

b. a deflection yoke which deflects and scans the electron beams so that both side spots of the three electron beams appear on the screen at an equal distance on both sides of the center spot when the three electron beams are not converged,

c. a convergence magnetic field generating means, said convergence magnetic field generating means consisting essentially of at least one pair of convergence windings which are respectively provided externally on the neck of said cathode-ray tube and are opposite from each other in reference to the axis of the cathode-ray tube and a convergence power supply which supplies the convergence current to said windings which forms said convergence magnetic field generating means forming a convergence magnetic field having which shifts only said side electron beams and has a field distribution which is symetrical and linear in reference to a second and third axis, said second and third axes being positioned with respect to each other and 45 with respect to said first axis, the plane formed by said second and third axes being perpendicular to the axis of the cathode-ray tube, wherein both side electron beams are symmetrically shifted in reference to the center electron beam, as a function of the deflection angle, in order to complete convergence of the beam spot trio through said convergence magnetic field.

2. An apparatus according to claim 1, wherein a deflection yoke deflects and scans the electron beams so that the distances between side spots and center spots appearing at two symmetrical positions in reference to the center of the screen are equal when three electron beams are not converged.

3. An apparatus according to claim 1, wherein said convergence magnetic field generating means is positioned such that the convergence magnetic field is induced at the deflecting position of the deflection yoke to shift symmetrically both side electron beams in reference to the center electron beam at the center of deflection.

4. An apparatus according to claim 1, wherein said at least one pair of convergence windings comprises two sets of said convergence windings arranged at positions at 90 from each other around the axis of said cathode-ray tube.

5. An apparatus according to claim 5, wherein said convergence windings are toroidally wound on a core made of a ring-shaped highly magnetic material which surrounds the neck of said cathode-ray tube about the axis of said cathode-ray tube.

6. An apparatus according to claim 5, wherein said deflection yoke is comprised of a ring-shaped yoke core surrounding the neck of the cathode-ray tube and a pair of coils which are opposed to each other and mounted on said yoke core, and wherein said yoke core is employed as the core for said convergence windings.

7. An apparatus according to claim 4, wherein said convergence windings are formed with frame-shaped windings which are provided at the positions around the neck of said cathode-ray tube in two axial directions 45 from the first axis and the direction intersecting said first axis at a right angle.

8. An apparatus according to claim 7, wherein said convergence windings are provided inside said deflection yoke.

9. An apparatus according to claim 1, wherein a set of convergence windings are wound in the form of frame at the positions around said cathode-ray tube in the axial direction and 45 at one side from said first axis.

10. An apparatus according to claim 9, wherein said convergence windings are arranged inside said deflection yoke.

, 11. An in-line gun type color television picture tube apparatus comprising:

a. an in-line gun type color cathode-ray tube in which three electron guns are arranged in a line along a first axis and the spots of electron beams from these electron guns appear along the first axis on the screen of the cathode-ray tube and are converged at the center of the screen,

b. a deflection yoke which deflects and scans the electron beams so that both side spots of the three electron beams appear on the screen at an equal distance on both sides of the center spot when the three electron beams are not converged,

c. a convergence magnetic field generating means which forms a convergence magnetic field having a field distribution which is symmetrical and linear in reference to a second and third axis, said second and third axes being positioned 90 with respect to each other and 45 with respect to said first axis, the plane formed by said second and third axes being perpendicular to the axis of the cathode-ray tube, wherein both side electron beams are symmetrically shifted in reference to the center electron beam, as a function of the deflection angle, in order to complete convergence of the beam spot trio through said convergence magnetic field, and wherein,

d. said deflection yoke is comprised of a ring-shaped yoke core, a deflection coil having two pairs of windings opposing each other and mounted on said ring-shaped yoke core wherein at least one pair of said windings are toroidally wound and a power supply which supplies the deflection current to said deflection coil, and wherein said convergence magnetic field generating means is further comprised of a convergence power supply which supplies the convergence current and a current superposing means which superposes said convergence current on said deflection current, whereby said convergence current superposed on said deflection current is supplied, from said current superposing means in the direction opposite said deflection current, to one winding of at least one pair of toroidally wound deflection coils and, in the same direction as said magnetic current, to the other winding for generating said convergence magnetic field.

12. An apparatus according to claim 1 1, wherein said current superposing means is comprised of a transformer which has a secondary winding provided with three terminals and the center terminal is positioned at an electrical center between the terminals at both ends, windings of the deflection coil which supply the convergence current are series-connected between the terminals at both ends of the secondary winding of said transformer, and one of said deflection current power supply and convergence current power supply is connected to the primary winding of said transformer and the other is connected between the intermediate connecting point and the center terminal of the secondary winding.

13. An apparatus according to claim 11, wherein one pair of windings in said deflection coil are toroidally wound and the other is wound in the form of frame, a pair of convergence windings opposing each other are toroidally wound at the positions from a pair of said toroidally wound windings of deflection coil in reference to the axis of said cathode-ray tube, wherein said current superposing means is comprised of a transformer having a secondary winding provided with three terminals and the center terminal is positioned at the electrical center of the terminals wherein a pair of said toroidally wound windings of said deflection coil are series-connected between both terminals of the secondary winding of said transformer, and one of said deflection current power supply and said convergence current power supply is connected to the primary winding of said transformer and the other is connected between the intermediate connecting point of a pair of said toroidally wound windings of said deflection coil and the center terminal at the secondary side of said transformer.

14. An apparatus according to claim 13, wherein a pair of said convergence windings are series-connected to a power supply which supplies the convergence current to said toroidally wound windings of said deflection coil.

15. An apparatus according to claim 13, wherein a pair of said convergence windings are parallelconnected to a power supply which supplies the convergence current to said toroidally wound windings of said deflection coil.

16. An apparatus according to claim 13, wherein the convergence current to be supplied to a pair of convergence windings is supplied from a separate power supply independent of the power supply which supplies the convergence current to said toroidally wound windings of said deflection coil.

17. An apparatus according to claim 11, wherein said two pairs of windings of said deflection coil are toroidally wound respectively on said yoke core and the convergence current superposed on said deflection current is supplied to said pairs of windings of said deflection coil respectively.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 5,806,757 Dated Avril 2%. l9'7h Invent or SADAYOSHI SARUTA It is certified that error appears in the above-=identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 5, line 1, change "5" to Signed and Seals this A nest:

RUTH C. MASON c. MARSHA Anesling Offi r LL DANN Commissioner nj'Parents and Trademarks Notice of Adverse Decision in Interference In Interference No. 99,381, involving Patent No. 3,806,? 57, S. Saruta, IN- LINE GUN TYPE COLOR TELEVISION PICTURE TUBE APPARA- 'liUS, filnal judgment adverse to the patentee was rendered Feb. 16, 1977 as to v c aims 6.

{Oficiml Gazette July 5, 1.977.]

UNITED STATES PATENT OFFICE @ETIFMATE 0F CQRRECTIQN Patent No. 5,806,757 Dated April 23. 197

Inven 0 SADAYOSHI SARUTA It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Claim 5, line 1, change "5" to 'r-.

gigned and ealcd tis .4 Nest:

RUTH C. MASON c. MARSHA Awnin Offi LL DANN Commissioner ojlarenrs and Trademarks Notice of Adverse Decision in Interference In Interference No. 99,381, involving Patent No. 3,806,757, S. Saruta, IN- LINE GUN TYPE COLOR TELEVISION PICTURE TUBE APPARA- TUS, final judgment adverse to the patentee was rendered. Feb. 16, 1977, as to claims 16.

[Ofiiciwl Gazette July 5, 1.977.] 

1. An in-line gun type color television picture tube apparatus comprising: a. an in-line gun type color cathode-ray tube in which three electron guns are arranged in a line along a first axis and the spots of electron beams from these electron guns appear along the first axis on the screen of the cathode-ray tube and are converged at the center of the screen, b. a deflection yoke which deflects and scans the electron beams so that both side spots of the three electron beams appear on the screen at an equal distance on both sides of the center spot when the three electron beams are not converged, c. a convergence magnetic field generating means, said convergence magnetic field generating means consisting essentially of at least one pair of convergence windings which are respectively provided externally on the neck of said cathode-ray tube and are opposite from each other in reference to the axis of the cathode-ray tube and a convergence power supply which supplies the convergence current to said windings which forms said convergence magnetic field generating means forming a convergence magnetic field having which shifts only said side electron beams and has a field distribution which is symetrical and linear in reference to a second and third axis, said second and third axes being positioned 90* with respect to each other and 45* with respect to said first axis, the plane formed by said second and third axes being perpendicular to the axis of the cathode-ray tube, wherein both side electron beams are symmetrically shifted in reference to the center electron beam, as a function of the deflection angle, in order to complete convergence of the beam spot trio through said convergence magnetic field.
 2. An apparatus according to claim 1, wherein a deflection yoke deflects and scans the electron beams so that the distances between side spots and center spots appearing at two symmetrical positions in reference to the center of the screen are equal when three electron beams are not converged.
 3. An apparatus according to claim 1, wherein said convergence magnetic field generating means is positioned such that the convergence magnetic field is induced at the deflecting position of the deflection yoke to shift symmetrically both side electron beams in reference to the center electron beam at the center of deflection.
 4. An apparatus according to claim 1, wherein said at least one pair of convergence windings comprises two sets of said convergence windings arranged at positions at 90* from each other around the axis of said cathode-ray tube.
 5. An apparatus according to claim 5, wherein said convergence windings are toroidally wound on a core made of a ring-shaped highly magnetic material which surrounds the neck of said cathode-ray tube about the axis of said cathode-ray tube.
 6. An apparatus according to claim 5, wherein said deflection yoke is comprised of a ring-shaped yoke core surrounding the neck of the cathode-ray tube and a pair of coils which are opposed to each other and mounted on said yoke core, and wherein said yoke core is employed as the core for said convergence windings.
 7. An apparatus according to claim 4, wherein said convergence windings are formed with frame-shaped windings which are provided at the positions around the neck of said cathode-ray tube in two axial directions 45* from the first axis and the direction intersecting said first axis at a right angle.
 8. An apparatus according to claim 7, wherein said convergence windings are provided inside said deflection yoke.
 9. An apparatus according to claim 1, wherein a set of convergence windings are wound in the form of frame at the positions around said cathode-ray tube in the axial direction and 45* at one side from said first axis.
 10. An apparatus according to claim 9, wherein said convergence windings are arranged inside said deflection yoke.
 11. An in-line gun type color television picture tube apparatus comprising: a. an in-line gun type color cathode-ray tube in which three electron guns are arranged in a line along a first axis and the spots of electron beams from these electron guns appear along the first axis on the screen of the cathode-ray tube and are converged at the center of the screen, b. a deflection yoke which deflects and scans the electron beams so that both side spots of the three electron beams appear on the screen at an equal distance on both sides of the center spot when the three electron beams are not converged, c. a convergence magnetic field generating means which forms a convergence magnetic field having a field distribution which is symmetrical and linear in reference to a second and third axis, said second and third axes being positioned 90* with respect to each other and 45* with respect to said first axis, the plane formed by said second and third axes being perpendicular to the axis of the cathode-ray tube, wherein both side electron beams are symmetrically shifted in reference to the center electron beam, as a function of the deflection angle, in order to complete convergence of the beam spot trio through said convergence magnetic field, and wherein, d. said deflection yoke is comprised of a ring-shaped yoke core, a deflection coil having two pairs of windings opposing each other and mounted on said ring-shaped yoke core wherein at least one pair of said windings are toroidally wound and a power supply which supplies the deflection current to said deflection coil, and wherein said convergence magnetic field generating means is further comprised of a convergence power supply which supplies the convergence current and a current superposing means which superposes said convergence current on said deflection current, whereby said convergence current superposed on said deflection current is supplied, from said current superposing means in the direction opposite said deflection current, to one winding of at least one pair of toroidally wound deflection coils and, in the same direction as said magnetic current, to the other winding for generating said convergence magnetic field.
 12. An apparatus according to claim 11, wherein said current superposing means is comprised of a transformer which has a secondary winding provided with three terminals and the center terminal is positioned at an electrical center between the terminals at both ends, windings of the deflection coil which supply the convergence current are series-connected between the terminals at both ends of the secondary winding of said transformer, and one of said deflection current power supply and convergence current power supply is connected to the primary winding of said transformer and the other is connected between the intermediate connecting point and the center terminal of the secondary winding.
 13. An apparatus according to claim 11, wherein one pair of windings in said deflection coil are toroidally wound and the other is wound in the form of frame, a pair of convergence windings opposIng each other are toroidally wound at the positions 90* from a pair of said toroidally wound windings of deflection coil in reference to the axis of said cathode-ray tube, wherein said current superposing means is comprised of a transformer having a secondary winding provided with three terminals and the center terminal is positioned at the electrical center of the terminals wherein a pair of said toroidally wound windings of said deflection coil are series-connected between both terminals of the secondary winding of said transformer, and one of said deflection current power supply and said convergence current power supply is connected to the primary winding of said transformer and the other is connected between the intermediate connecting point of a pair of said toroidally wound windings of said deflection coil and the center terminal at the secondary side of said transformer.
 14. An apparatus according to claim 13, wherein a pair of said convergence windings are series-connected to a power supply which supplies the convergence current to said toroidally wound windings of said deflection coil.
 15. An apparatus according to claim 13, wherein a pair of said convergence windings are parallel-connected to a power supply which supplies the convergence current to said toroidally wound windings of said deflection coil.
 16. An apparatus according to claim 13, wherein the convergence current to be supplied to a pair of convergence windings is supplied from a separate power supply independent of the power supply which supplies the convergence current to said toroidally wound windings of said deflection coil.
 17. An apparatus according to claim 11, wherein said two pairs of windings of said deflection coil are toroidally wound respectively on said yoke core and the convergence current superposed on said deflection current is supplied to said pairs of windings of said deflection coil respectively. 